Helix-loop-helix transcription factor E47 activates germ-line immunoglobulin heavy-chain gene transcription and rearrangement in a pre-T-cell line

E47 is a helix-loop-helix transcription factor that binds to sites in the immunoglobulin heavy-chain and κ light-chain gene enhancers. Other proteins of this type are involved in cell-type determination. A possible role for E47 in B-cell development was tested by overexpressing a cDNA encoding E47 in the pre-T-cell line 2017. We found a dramatic activation of a germ-line heavy-chain gene transcript in these stable transfectants and an equally large induction of immunoglobulin D-to-J rearrangement, the first recognized step in B-cell development. Germ-line κ light-chain gene transcription and rearrangement were unaffected, but transcription of the recombination-activating genes RAG-1 and RAG-2 and the lymphoid-specific transcription factor Oct-2 was increased. These T cells did not transcribe their rearranged DJ alleles, however, and failed to progress to the next stage of heavy-chain gene assembly, V-to-DJ rearrangement. Because transcription factor E47 can induce pre-T cells to carry out events of B-cell differentiation, it may be a crucial determinant of the earliest stages of B-cell development

Mutations that disrupt DNA binding and dimer formation in the E47 helix-loop-helix protein map to distinct domains

A common DNA binding and dimerization domain containing an apparent "helix-loop-helix" (HLH) structure was recognized recently in a number of regulatory proteins, including the E47 and E12 proteins that bind to the kappa E2 motif in immunoglobulin kappa gene enhancer. The effect of site-directed mutagenesis on E47 protein multimerization and DNA binding was examined. Mutations in either putative helix domain disrupted protein dimerization and DNA binding. No DNA binding was observed when mutations were introduced in the basic region, but these mutants were able to dimerize. These basic region mutants were not able to bind to DNA as heterodimers with the wild-type E47 proteins, demonstrating that two functional basic regions are required for binding to DNA. Therefore the basic region mutants are "transdominant.

Experimental and Theoretical Studies of Distribution of Vacancy Clusters in Depth of Material Irradiated by High-Energy Particles

Non-destructive method of positron depth sensing of the radiation defects in solids was proposed and implemented. The depth distribution of vacancy clusters in molybdenum irradiated by protons with energy of 30 MeV was found based on the experimental data. Theoretical calculations of this value were made and sufficient agreement between calculations and experiment was obtained

Organization of virtual interaction in the context of the coronavirus pandemic

The organization of the educational process should be carried out taking into account the epidemiological situation and following the requirements that are due to quarantine measures. The leadership of vocational schools is looking for ways to conduct classes in a safe environment, assessing the potential risks for teachers and students. Higher schools implement the possibilities of electronic technologies as a factor in ensuring the safety of subjects of the educational process for communication between students and teachers at a distance. The purpose of the article is to review the experience of organizing virtual interaction between students and teachers within the framework of e-learning during the spread of coronavirus infection. The article reveals the possibilities of electronic technologies that allow communicating at a remote distance. The preparation of students in critical conditions is carried out using various electronic means that promote active interaction. The results of the study reflect the opinion of students of higher educational institutions about the use of virtual interaction tools. The results obtained using the Likert scale allow us to say that the majority of the respondents are active participants in virtual interaction and are ready to continue to communicate using the presented means despite the existing difficulties

Gli2 and MEF2C activate each other's expression and function synergistically during cardiomyogenesis in vitro

The transcription factors Gli2 (glioma-associated factor 2), which is a transactivator of Sonic Hedgehog (Shh) signalling, and myocyte enhancer factor 2C (MEF2C) play important roles in the development of embryonic heart muscle and enhance cardiomyogenesis in stem cells. Although the physiological importance of Shh signalling and MEF2 factors in heart development is well known, the mechanistic understanding of their roles is unclear. Here, we demonstrate that Gli2 and MEF2C activated each other's expression while enhancing cardiomyogenesis in differentiating P19 EC cells. Furthermore, dominant-negative mutant proteins of either Gli2 or MEF2C repressed each other's expression, while impairing cardiomyogenesis in P19 EC cells. In addition, chromatin immunoprecipitation (ChIP) revealed association of Gli2 to the Mef2c gene, and of MEF2C to the Gli2 gene in differentiating P19 cells. Finally, co-immunoprecipitation studies showed that Gli2 and MEF2C proteins formed a complex, capable of synergizing on cardiomyogenesis-related promoters containing both Gli- and MEF2-binding elements. We propose a model whereby Gli2 and MEF2C bind each other's regulatory elements, activate each other's expression and form a protein complex that synergistically activates transcription, enhancing cardiac muscle development. This model links Shh signalling to MEF2C function during cardiomyogenesis and offers mechanistic insight into their in vivo functions

Gli2 and MEF2C activate each other's expression and function synergistically during cardiomyogenesis in vitro

The transcription factors Gli2 (glioma-associated factor 2), which is a transactivator of Sonic Hedgehog (Shh) signalling, and myocyte enhancer factor 2C (MEF2C) play important roles in the development of embryonic heart muscle and enhance cardiomyogenesis in stem cells. Although the physiological importance of Shh signalling and MEF2 factors in heart development is well known, the mechanistic understanding of their roles is unclear. Here, we demonstrate that Gli2 and MEF2C activated each other's expression while enhancing cardiomyogenesis in differentiating P19 EC cells. Furthermore, dominant-negative mutant proteins of either Gli2 or MEF2C repressed each other's expression, while impairing cardiomyogenesis in P19 EC cells. In addition, chromatin immunoprecipitation (ChIP) revealed association of Gli2 to the Mef2c gene, and of MEF2C to the Gli2 gene in differentiating P19 cells. Finally, co-immunoprecipitation studies showed that Gli2 and MEF2C proteins formed a complex, capable of synergizing on cardiomyogenesis-related promoters containing both Gli- and MEF2-binding elements. We propose a model whereby Gli2 and MEF2C bind each other's regulatory elements, activate each other's expression and form a protein complex that synergistically activates transcription, enhancing cardiac muscle development. This model links Shh signalling to MEF2C function during cardiomyogenesis and offers mechanistic insight into their in vivo functions

Photothermal Activatable Mucoadhesive Fiber Mats for On-Demand Delivery of Insulin via Buccal and Corneal Mucosa

Electrospun fiber mats loaded with therapeutics have gained considerable attention as a versatile tool in the biomedical field. While these bandages are largely based on fast-dissolving polymers to release the cargo, stimuli-responsive fiber mats have the advantages of providing a timely and spatially controlled drug delivery platform, which can be refilled and reused several times. These benefits make electrospun fiber patches original platforms for painless and convenient on-demand hormone release. Because of the high need of more convenient and non-invasive methods for delivering insulin, a hormone that is currently used to treat hundred million people with diabetes worldwide, we have investigated the tremendous potential of reduced graphene oxide modified poly(acrylic acid) based fiber mats as an original platform for buccal and corneal insulin delivery on-demand. The PAA@rGO hydrogel-like fibers rendered water-insoluble by incorporating β-cyclodextrin, followed by thermal cross-linking, which showed adequate tensile strength along with high adsorption capacity of insulin at pH 7 and good recyclability. The fiber mats maintained good fibrous morphology and high loading efficiency even after five loading-release cycles. The mucoadhesive nature of the fibers allowed their application for insulin delivery via the eye cornea and the buccal mouth lining, as evidenced in ex vivo studies. Insulin loaded PAA@rGO hydrogel-like fibers showed an insulin flux via buccal lining of pigs of 16.6 ± 2.9 μg cm-2 h-1 and 24.3 ± 3.1 μg cm-2 h-1 for porcine cornea. Testing on healthy adult volunteers confirmed the excellent, mucoadhesive nature of the bandage, with three out of six volunteers feeling completely comfortable (note 8.3) while wearing the patches in the buccal cavity.The Centre National de la Recherche Scientifique (CNRS), the University of Lille, the Hauts-de-France region, and the CPER “Photonics for Society” are acknowledged for financial support. This work was partly supported by the French Renatech network. A.V. thanks the i-SITE foundation of the University of Lille for a PhD fellowship. This project has received funding from the European Union’s Horizon 2020 Research and Innovation Staff Exchange (RISE) Marie Skłodowska-Curie Actions under grant agreement No 690836.Peer reviewe